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A272916
Numbers that are a product of two Fibonacci (A000045) numbers or a product of two Lucas (A000032) numbers.
2
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 18, 21, 24, 25, 26, 28, 29, 33, 34, 39, 40, 42, 44, 47, 49, 54, 55, 63, 64, 65, 68, 72, 76, 77, 87, 89, 102, 104, 105, 110, 116, 121, 123, 126, 141, 144, 165, 168, 169, 170, 178, 188, 198, 199, 203, 228, 233
OFFSET
1,2
COMMENTS
Conjecture: if c and d are consecutive terms, then d - c is a term.
LINKS
EXAMPLE
Equals union(A049997, A272909), in increasing order.
MATHEMATICA
z = 400; u2 = Sort[Flatten[Table[Fibonacci[i + 1] * Fibonacci[j + 1], {i, 1, z}, {j, i, z}]]];
v2 = Sort[Flatten[Table[LucasL[i]*LucasL[j], {i, 1, z}, {j, i, z}]]];
u = Take[Union[u2, v2], 200] (* A272916 *)
d = Take[Differences[u], 200] (* A272917 *)
CROSSREFS
Cf. A000032, A000045, A049997, A272909, A272917 (difference sequence).
Sequence in context: A232528 A254075 A140401 * A138389 A346288 A032963
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, May 10 2016
STATUS
approved